mailbox: implement a sandbox test

This adds a sandbox mailbox implementation (provider), a test client
device, instantiates them both from Sandbox's DT, and adds a DM test
that excercises everything.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org> # v1

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 89300096a5a..686c215aea7 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -216,6 +216,17 @@
 		};
 	};
 
+	mbox: mbox {
+		compatible = "sandbox,mbox";
+		#mbox-cells = <1>;
+	};
+
+	mbox-test {
+		compatible = "sandbox,mbox-test";
+		mboxes = <&mbox 100>, <&mbox 1>;
+		mbox-names = "other", "test";
+	};
+
 	mmc {
 		compatible = "sandbox,mmc";
 	};